The "DICE" study is a multi-center study designed by the Asthma Clinical Research Network (a network of 6 research centers supported by the National Heart, Lung, and Blood Institute) to determine the dose-systemic effect relationship of inhaled corticosteroids in adults with mild asthma. The study involves doubling the daily dose of different inhaled corticosteroid preparations at weekly intervals; the principle effect measured will be the overnight secretion of cortisol as measured in serum samples obtained hourly between 11 p.m. and 7 a.m. Other outcomes measured will be overnight urinary cortisol, the rise in cortisol provoked by a low-dose ACTH stimulation test performed at 7 a.m., serum osteocalcin, and urinary N-teleopeptide. The protocol involves 7 visits, 5 of them requiring an overnight stay in the GCRC for overnight urine collection and hourly blood sampling. Our sample size estimate is that the 120 subjects will need to be studied (20 at UCSF; 100 at the other participating sites). We propose to administer placebo aerosol over the week prior to the first overnight stay and then to give doubling daily doses of one of the 6 inhaled corticosteroids by its standard delivery system. From the results of this study, we plan to calculate the dose-systemic-effect relationship for the 6 preparations and to identify the doses with equisystemic effects for a later trial comparing clinical efficacy.